A photovoltaic cell is a generator, commonly called a photostack or a photovoltaic cell that makes use of the photovoltaic effect. The photovoltaic effect can be defined as being the appearance of a potential difference between two layers of a semiconductor slice in which the conductivities are opposite, or between a semiconductor and a metal, under the effect of a light stream. A photovoltaic cell generates a direct current.
A semiconductor is generally a solid material in that the intermediate resistivity between that of the metals and that of the insulation materials varies under the influence of factors such as the temperature, the lighting, the electric field, etc.
The main known semiconductor materials are germanium, silicon and selenium.
We are already familiar with a portable solar charger, described in WO 2004/077577. This charger includes a flexible photovoltaic panel that is permanently fixed onto a flexible textile material. The said solar or photovoltaic panel can be stitched along its inactive edges to the flexible textile sheet, or glued, or indeed welded by the application of heat or ultrasound.
The manufacture of this type of solar charger is still artisanal in nature even today. There are no techniques up to this present time that can be used to manufacture assemblies resulting from the assembly of a textile sheet and one or more flexible photovoltaic panels that are of large dimension in an industrial manner.
These small-dimension chargers have a small collection surface for the incident rays. Moreover, when they are arranged to form solar protection panels, to constitute a blind for example, the storage enclosures have to be redimensioned, if only to receive the textile sheet in the rolled state, since the thickness will have very significantly increased or even doubled once assembled with one or more photovoltaic panels. In addition, one notes the formation of fatal folds during use, and these may be able to hamper the rolling and its introduction into the storage container, or indeed that damage the aesthetic appearance of the composite when it is in the deployed position.